SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8b383ff2316d919e4bdc68cd18577eb697efb3ec2f8b09259eaf8e511c451b7' 
  AND token = 'OPlQDAlUmzhY0s9VHibPTKC0hJ+GAOH6qOqigiDtLKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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