SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47cbff1aa2124b3fd354dd481ec0cb8c0bed414ef48c88c43e2576906e7f6da9' 
  AND token = 'V/BxAZzpRirEswGT+bImC8FnSjE/bBNDVk+6MeXqFlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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