SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9a757bb3c66284e29035a7cf489dcfffac1d08d3a3f36ac15137a5a5e3c5650' 
  AND token = '8jgfX9PYCuxCUuHyN/FjXzuUZN2IQZ+H2KiYZN5+w9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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