SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe63f5d8677bd35226866e959af770abb05bcb95f941106edfd759aefb4e2e71' 
  AND token = 'mEew+QVSgU8PAZsEtMsiWsmSQZa2iZQTCCTd9QWWe6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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