SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7371397e73085436a9b7b5722d14c25fc81a61bcf51b4fb8c1f35fb259adb915' 
  AND token = '8M1O0h6DPbEkyBbsO+4c2SoiwQZrzSbB69lXmAgFpzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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