SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a971e698c0bc7cbb4cb55f1132e11e692c1a195674f99e07ca6eb59b70c4bebb' 
  AND token = 'ROb5p/Ajhv73FiYIPcY12gw/5whRPO+cdwmtXNzaq5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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