SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6304a3de269c2413312a006efcd206bdb022b7dc95f6631475a05cba7231cf28' 
  AND token = 'E9LLljoFTGPjezD/mc4pZVx6eQl5ZUlbGLf20BfeH2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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