SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efb261d277fdb1f8d8a7cf4ac94441f2b674070f086492633a85bc0e8e1e9c96' 
  AND token = 'oH0/7Va9NNytxhLyYsEMt/nBulWHkYbJCFoDQDDtAGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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