SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd88a1b92b0fcaa01cae1bda99b6dad1bcad8c537753424232fd8d11096e5d0b4' 
  AND token = 'TKfONU9Vj/BRU6dX3gNDEq/GjZGLvgWrxfSbZvRmOQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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