SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27b4a5aad51a200e3296a6eebe427fb19dedda81b630ac24f8e9c6acbd951bb6' 
  AND token = '7+rzQpUPxCN64BZynr0cQr8L1L+dOIHW5k8NeBfuNPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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