SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c773fffbd7e312998c2411a72136efca8fd34c9190b114565509a8cef5faf65' 
  AND token = 's44RMBISoWIZVJ08o/eirPhCDsEHGLoUbd6JNGoEm+4=' 
  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"
    }
  }
}