SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f1027ca3801ff1f84fb21b451644afef5fa182eba819336df7b74f30d70492d' 
  AND token = '6Dk5ppfxcv6GJDgN8tJ9KblaObmmcZn7qiMfpO34OO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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