SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d9183d3faae86174be16c8761b342c9596c756f61327536b4bc426d2196052b' 
  AND token = 'cY3Ay91GH8huXnj9BoDxBLEUHo9Ja3mtmU+f9qXVWhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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