SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a89e47aa8d40a441ccbaeed7cdf1d50b7bd7aafe7eb6e89e7802545a8ff8a3' 
  AND token = '7ouNNxDmszw3ohDhbQt4bfkShPnEHPJjhddl6tKjB7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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