SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dde6ee90b008a2faf95fa06fdb9fa1f3837181952f527effd3482c3895451825' 
  AND token = 'bIoju49lyJQgo1p55OAcn8tVj9BU/TDnAVDvekkXD9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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