SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dc7809157e32b2b6c9fab2046a23331e8bbab307e871ea9a8b09a4db6ccce5b' 
  AND token = 'wG6JpQi8Ia7pvrIbQe/5E1lleqDpDrB7AReJkmpCyZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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