SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c448f1ce08e25ced2f3e0f1d2c1c6b408f1aab135d1faa6167fdee72549dbb1' 
  AND token = 'gK5qhkJOs6pH6VOZvLFIrR6LYhaYeSbXSa3JRLEkdak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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