SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2941c73824784b710bdcbb133e3bdb7c33d3794692dd8d7e9716412b15b5545a' 
  AND token = 'qJWrgWuRe6UAMgBcymkcyHltgQaWp4mgrX8O+aGp8GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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