SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ad8cdc32e85a739921648f17440ed4ce8f1ef14c3be7e99235ff838d7484e9d' 
  AND token = 'jaLB9Q+QSUehOX1t+tYvFUO1Rwk2F5VEg1JAXlqHhxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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