SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '3587dd43ec2dc938bb2e986cf1316c541474e196581f2814a15c4afd502edff4' 
  AND token = 'YYbaLUu5A9tVUG7pxLBWgDJfIkb+lXpAMM8VS38/Fd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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