SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dba39aaabcd9eab3fc0b9982cc5793db216b283169ec1b88dd171bac3a0e999e' 
  AND token = '4nLe56XN6IAlS+9pKYj40hrLNYRlQm+9h2H1K1Tjfp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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