SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18071c55678e177214393da128cd059416d61ec4e0d746e9ec69ed7ccbfb0f38' 
  AND token = 'JgMaJgrctRsGbbCoSU9RBlEPn18uHCU+FYfjn0AzvOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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