SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1c2c4ffbc6f5884f002f264e9f2c20c7fed41877d878a77f1bda08015d571ec' 
  AND token = 'cL6oYwEmdYat0RIMVKFsR3iCSPV7JJ7fBmkcJbnokrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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