SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '295812d465e93f10004b45e810fd19e9b6564b186848732cfae527062971ebcc' 
  AND token = 'EAsMtNAKCsP6hH2hTiqou334JKeoi5SEUPgoCXgQCPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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