SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9760480a2920ddaa668eac25f220cff2193fb19aa3d7f95abde2bdc29055cff2' 
  AND token = 'L1ilaf4rIHxxzXhCvYEHpEMdOlKPqFevj/Q7ldxqizk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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