SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feeae0ec3eb439d2d740e40b114e0d3fe23b624e2ef71356d618b7925ad0c767' 
  AND token = 'lLSlSEHNJTesdED+hzjvWbvDSR6HFADp66UJiBvDvvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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