SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fedf707af19e621e2930c2fc27a1fead24014c1c25afd3679b893f3341e0f69' 
  AND token = 'QhBOA2kzDauVmaNpzGN0xXyUW2BIk3qL0eexrpP7NjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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