SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8428505ae34387b125da38e5801c279f0576389b4d0fbc44ff98ee971168bd87' 
  AND token = '5/vPCzoVGY/U/A4HiGHeQl4vOp/XpxOUSxkgpRReAy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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