SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f561354855368fe7a9a9e5afeafc8516485bc60a0e7a86a5617d2f147c16169f' 
  AND token = 'N2hedviOnkSxbMRKoQE2U8jUbT0afZ06v0d6x0/0RIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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