SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57afcd318c8068e4447867ec57864ba61e7c3491b192645065ad1d403779b72e' 
  AND token = 'DRmTLwegOjBiHlwJqLORuckx4XU+lvJGY2JRC9ZgBbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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