SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5e7eb8ab09847ed2a09d5900ed92711f06df4af68950d71f3e5eb6b23bd97de' 
  AND token = 'kTIxghQ5HgP4/xQbjovwXa/aMbAx4+T+Ui9CgHREst4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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