SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a719aa3ca83bc4bfb64bddefde846feb93f4d89fe8fc9460963f840bbb1aaa95' 
  AND token = 'd412a1A+kzlX/d26m15G+Se7969zLGJRsR3NueUgVXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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