SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7be25bb630f0abb5b437b04c6f0f231a0fbd16dd750cde557c864b53b7698ea' 
  AND token = 'hJv15Iv/+qkjkkYtktqpwmVKfa1GItzWM8lwYKw0LdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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