SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '015c273a5c4a1678c2bed8618532901d73d75c7aa2a9ddc8ccbce1db52a26b07' 
  AND token = 'cnNaraTQo1udK3DH+m/0bri3VvmaHGWUi3oU/kL0zJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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