SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de252a84a64c4017876163a005cfda58e6215863593cea618fd8160e5e97123c' 
  AND token = 'qwhzR2YG7JCkFxF2chSYpUV2hk9m2DIGcldxFCYjNfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}