SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef31692c7420aac7a24cde0c472a69c0c2fa42e05aee86dca0cae7b4d8204720' 
  AND token = 'kOumZlL7gitjFMd/AqNp/a1TnSdTinbeKVZI+AEmrZA=' 
  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"
    }
  }
}