SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fa18c30c6c5204c5998d7eb5df4f2f447c952f72cb19230cd9e29f2f31d4f03' 
  AND token = 'Ut3cDSts69QXGvORonlOYQYsWehl7J8ZSRFppzkYTMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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