SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04213ad745d107bb193fdf14c8661e2ed7907486fbe2f3b10d514ee2dc15a063' 
  AND token = 'CyX++xnCAiHFZgLEWPMQymM9Q4IJtRYQRTylakPfF8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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