SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cac8e4a118c8dcfa4d2679e11699f87aff92568cebb891155b41e690fc3672e5' 
  AND token = 'sa0w5x3Shcmk4BQyroDpuIpcQjisvUw3oWvY7nh77uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}