SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa370d261532ed5db0f8c8b38f3387c88a02a8fbaaa7a70161adae5db4ecc40b' 
  AND token = 'K481632j1foXJOaXXjriSr1K60gu4x4smF2TfQD/g1k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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