SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4528e90b5d7cefabcecfede0deda888d9ade63b5be070e9bbdb018db2bfbc173' 
  AND token = 'ujgLRfQj8/4khFYPJLC4n+RO6g2mXnb0oJkeyHJJUy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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