SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db2acab41b00f5546ac44eb35c3010472051af674484d421f5a354574c61dd1b' 
  AND token = 'Vc3jBURdwwsa+H8JFewPzLDPPvMP+WxXirxEANMNK0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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