SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d044fed1c7713d9e16e436d3dc9d3044d54f62db063d0691aad90d61d556674' 
  AND token = 'RBxg0jU6eAGROGJUrg7JJjnXyqYnHywAeMsg+99bfSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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