SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b692fc2b05308788b4c19b8cb4dd78a57c1a394ed3ae5a916b12d6beb3bf28da' 
  AND token = 'csSRgM1IbfsPKOkt6Ngko2lh6m06HB9Cx2KqFV1hwec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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