SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba54bdd7e16c014ffe7e938c508ab221f764bfda09230c8fb2be9fb796a38f47' 
  AND token = 'B2x9HBHxHKC5bTZZ2sLZGI3BjPnykUJFQGNOAhOSQW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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