SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9625bf4437ce7fe6ab80eb08046207696ca6ba8ef1c4d1226e6087d4b6265ad6' 
  AND token = 'JxhKbmmtvZGqjSYrv0JtctidfEpnfsUYS+Y/RQ1VMMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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