SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '52f1c444a968ff953e08a5e66cf2d7427351731fd74923c66ad06c3fffd08ce8' 
  AND token = 's5GXRG1AImeZbbY68BQtK7Is0+17uLmQIFhF9q0kqcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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