SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bcf71207a494ee694163942d8a2afe188d8023b99c4015539ff8ef15965010e' 
  AND token = 'ZwxEoS1kGjGvEKXpi14MDyw3I/VGEsSFJtVdUjhvlLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}