SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '666e979fc7202ebb18c3dba6935e42a6e9678f4d10faaec7084cc47437db15ae' 
  AND token = 'XIOqPVb1L8TqqCAjSSLTzJqTwDtdpaF+HDr4EhICAQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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