SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee852be36b49c07785a164be989d4bf9570d5d06979597276a8316252de452da' 
  AND token = '2BBgk5pADmV3DBOAHCxu2kYeSEMJt6sMoH3p2srtDuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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