SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '53b1f7310db6e9f037549b709b83cec35a2c0dfcd48b753677224e7b4644a512' 
  AND token = 'ELuX4mD+3oxON+imkVhSDIu6RAZKKObDcTPBWF+Mbhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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