SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '692b5cb60d2f1e1df32c6a7048860cd034b65b0bffd710882bc6708ddbc8692e' 
  AND token = '7pgDKIOicJqGlDPdxHMy3/z7TlbQJfPR6+OAesFxGnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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