SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9f0e080d09f98fc638628ae5989982f71875a2ba799fe9dc11069488898cd42' 
  AND token = 'phL/GpRBFQLR2WlzS14Pb23u2tP4S9I/jN7mTkIHNHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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