SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '977fc9aded0490e044d5ca7a0095421d840323fea8ff6f57f5aea3c61fdaea02' 
  AND token = 'IXfONUq0gNd/vEXfda4G6hT5NdaJFVX/95MW+oaGAb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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