SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d9ee38e5b028db6bb7d3aa058cddad84d7557799243cb517d47d4d8ed48672f' 
  AND token = 'O29hE+9qeLhlmWOPjnHKI1vrrGlNoXv/XcC5fV9YP0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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