SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '807322290158f8ebf1916a5f0dbd3c52f2ec898cd885607baf648a37d9871ff6' 
  AND token = '4UxIeSuqaYmg+fyM4qEaZOU5cRVw/DTjpVCZjGWm5rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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