SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a7e3f6abe256b094873ba83f566e8526052523927fe36442c6b11ab4b2fcfd2' 
  AND token = 'dt0cCA9xR6ZYW/1nxxPuYjansr7IQHtWQBlAkaI9/NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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