SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f0d556b6b560a41efd50095d43157d024f732f635aba37347aac26aa98ec8c7' 
  AND token = 'wkgUZl+TJyWcEYHWRWkWjg7HOMnczdqlKvZgmki4oDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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