SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8186ee4caf59d00706863a9aa4a79b7bd1976a0cb58779e6540682065db833b7' 
  AND token = '9n06ixs2+Bik9rluTEyHpTpfr4RUzoaEayQHwbvwcuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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