SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aea66c9ea20092f5b47fa90d12800167e090556ded10a1238a4e2d3cb8ef306a' 
  AND token = 'CJdGGE0N9N+JVGeYw6vY7WDAGJXKE3lUx0lXb1NwexY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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