SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0437b564409390cb9a488b45ba89d961f8d74cb4d636efccf8dbf8435368d39a' 
  AND token = '6Gh5AzmKy1wuQNFi40pzYf92qP1iYkbCmrwPauyga9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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