SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f9bfad80a935b8092cb43af70ad1e990238d932f93b74c9c66dd0f62d88642c' 
  AND token = 'ihWjw4++03QW0YMUrDdZevJPeo84YlsjUgc5Zr9dgHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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