SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '353cc414bcc56e304ac88b6e7f098a3f75ec6a798a58f750f98479f500f46b60' 
  AND token = 'XL6Y0rYXj20CRD3GgkI8Q4jYx6imfYGQ1xk7uwh39ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}