SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5232a443ce02e53e743e2fa2063014332331479c8e2ae334c2df01de27251eb' 
  AND token = 'twyq/Gv2qMMkkmNrOC5NxRcBIoEnWtHXxTpqs6YIvsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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