SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3150ff702a40ac3c29cfcb72223d0f9a1121ee7ea75864367990c6e891bf3a1' 
  AND token = 'mLZOE58xUO6tMQg0Ink9vq1J0zTtTh4XzVFjvg4OxyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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