SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9d737a877ae1889c16fd6d9d616fe495100e66ff581200815e1747aac31c30b' 
  AND token = 'XEc1diPMJzi/DJvkQC7/hxBYR6jh0MwQAAG0zVFAGLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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