SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89d831146898dc9aca31803c49532bff1db2e0626fbf6cdc0bc0cb113a59d554' 
  AND token = 'F4ZUX1c7kbegnZQ25/EAz/3UuQQHTD8jzi5uR8DgIzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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