SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '052deaff1a5176e2dea219850c3b765c974145be20a976a73f1e14db302e916b' 
  AND token = 'zmR/cPtHbDnq3GARZ9YHgUPVFxXb/kofXnnyEJYOKNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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